A huge number of video game systems have been proposed. These systems include, for example, systems comprised of a special device for home use and a television monitor and systems comprised of a special device for business use, a personal computer or a workstation, a display and a sound output device. Any one of these systems includes a controller used by a game player for operation, a storage medium storing game program data, a CPU for executing controls to generate images and sounds based on the game program data, a processor for generating images, a processor for generating sounds, a CRT or like monitor for displaying images, and a loudspeaker for outputting sounds. CD-ROMs, semiconductor memories, cassette-type storage mediums having a built-in semiconductor memory are frequently used as the above storage medium.
As one kind of games executed by such game systems, it can be considered to simulate apparatus gymnastics such as the vaulting horse and the horizontal bar in a game space. Specifically, in an apparatus gymnastic game such as a vaulting horse game or a horizontal bar game, a play character who is a gymnast is caused to appear in the game space displayed on a monitor and perform a specific technique, an evaluation point is given to the play character depending on the degree of difficulty and degree of success of the technique performed, and ranking is determined based on the evaluation point.
In the gymnastic game as above, a plurality of techniques having different degrees of difficulty are prepared in advance. For example, the play character may be caused to perform a technique selected by operating an operable member such as a selection button based on an instruction displayed on a game screen. However, if a game can be proceeded by such a simple operation, it lacks ingenuity. Therefore, even if a game player is interested when he starts playing this game, he may get bored soon.